Clinical Core: Summary/Abstract: The Clinical Core of the Program Project Grant (PPG) is responsible for cognitive and clinical evaluations for all participants enrolled in the PPG. The Clinical Core coordinates and conducts neuropsychological testing, neurological exams, collects medical history data, administers depression symptom questionnaires, and completes interviews about and rates levels of daily functioning of participants. This information is used to make cognitive diagnostic classifications in aging, specifically normal cognition vs. mild cognitive impairment vs. dementia. The Clinical Core assigns diagnostic categories via a multidisciplinary consensus conference, which it organizes on a bi- weekly basis. Diagnostic categories and cognitive measures are used by Projects 1, 2, 3, and 4 for initial study screening and as key cognitive outcomes in the Aims of the PPG. The Clinical Core transfers all cognitive and clinical data collected to the Imaging, Methodology and Statistics Core and assists in merging clinical data with neuroimaging data. Finally the Clinical Core will recruit and coordinate new autopsy cases in support of Project 3.